This invention concerns metal finishing barrels used in the cleaning, plating, phosphating, etc. of metal parts in bulk.
Metal finishing barrels are constructed of materials which will not be attacked by the various processing solutions such as polypropylene or stainless steel. These barrels are perforated so as to allow the parts to be immersed when the barrel is lowered into a tank of a plating or other processing solution. The finishing barrel is rotatably mounted on a support structure to allow it to be rotated while immersed in the tank to tumble the parts, insuring even processing, and a gear is affixed to one end of the barrel for rotating the barrel with an electric motor.
One or more removable covers are installed over a loading/unloading opening provided in the side of the barrel. The covers must be closely fit to the opening to insure that small parts will not be captured in clearance cracks or escape through gaps between the cover and the barrel. The covers must also be held securely to withstand the heavy loads imposed by the weight of bulk quantities of metal parts as the finishing barrel is rotated.
These requirements have led to the development of an interlocking tab cover securement in which a series of tabs on each side of the cover are slid beneath barrel tabs projecting towards the barrel opening to secure the cover in position. A separate cover locking system is needed to positively prevent the cover from shifting back to release the tabs during processing. This locking system has previously taken the form of a polypropylene nut piece threaded into a gap between two covers arranged in end to end alignment over the opening, preventing the covers from shifting back to disengage the tabs.
This arrangement has worked very well, but requires the threading and unthreading of the separate nut piece, significantly slowing the process of installing and removing the covers manually. Further, this system makes it difficult to automate the cover installation and removal process, which automation is often desirable.
In the parent application Ser. No. 09/813,649, filed on Mar. 21, 2001, a processing barrel cover locking system is described and claimed which is positive and secure while not requiring separately installed locking system components, speeding up the installation and removal of the covers.
This system involves a handle which is mounted on a spring blade which allows the handle to move out when being removed and is urged back when released to move into a positive blocking position preventing endwise movement of the cover so as to be securely captured by the tabs.
It is the object of the present invention to provide an automation apparatus for automatically installing and removing covers on metal finishing barrels which are secured by tabs interfit by an endwise sliding of the cover in the barrel opening, and locked by a spring blade mounted handle.
The above recited objects of the invention, as well as other objects which will be understood upon a reading of the following specification and claims, are achieved by an apparatus utilized with a barrel cover having a cover handle assembly mounted thereto including a spring blade attached at one end to the cover. The cover and barrel are each formed with a series of interfit tabs, which allow the cover to be placed into the barrel opening with the tabs offset. When the cover is slid endwise in one direction, the cover tabs are positioned lying partially beneath the barrel tabs to be interengaged and hold the cover over the barrel opening.
The handle assembly is aligned between successive cover tabs to engage a barrel tab when the cover is pushed into place onto the barrel opening, but the spring blade mounting allows the handle to be moved out to allow the cover to be advanced so that the cover tabs are positioned beneath the barrel tabs. The cover is then slid to a tab-engaged position with the cover tabs partially lying beneath the barrel tabs to secure the cover in position over the barrel opening.
When the handle is released, the spring blade causes the handle assembly to move back down against the cover, with the handle assembly then located just to one side of one of the barrel tabs. The handle assembly has a locking portion which is then located to one side of that barrel tab, acting to block any reverse shifting of the cover back out from under the barrel tabs, to positively lock the cover in the secured position. A separate feature can also be used instead of a barrel tab to interact with the handle assembly locking portion.
The handle assembly moves away from the cover when the handle is pulled as the cover is being removed against the force generated by the spring blade, to elevate the handle blocking portion above the barrel tab.
This outward movement of the handle assembly allows the cover to be slid back out from under the barrel tabs and then lifted off the barrel opening.
In the automation apparatus according to the invention, the finishing barrel is first transported to a cover installing/removal station in a predetermined angular orientation, where the automation apparatus is shifted endwise to be accurately located laterally relative to the barrel in preparation for a cover removal and installation at the station.
The automation apparatus includes a series of cross slides advanced to the barrel before and after it is located in position. An angle slide moves down to the cover with a fork capturing an upright piece on the cover. A cam carried on a first sideways moving slide included in the apparatus acts on a rod on the cover handle, camming the handle outwardly. The first slide also advances a series of rods into bores each in a respective one of a series of upright pieces attached to the cover. The cover is then advanced in the same direction by a second sideways moving slide to move the cover tabs out of engagement with the barrel tabs and allow the cover to be lifted off the barrel by the motion of the angle slide. The cover is installed by a reverse sequencing of the various slides.